Frequencies for first 10,000 rows of nprev28 variable in natl1981 dataset :

  Number of |
   Prenatal |
     Visits |
     Recode |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        142        1.42        1.42
          2 |        200        2.00        3.42
          3 |        181        1.81        5.23
          4 |        228        2.28        7.51
          5 |        290        2.90       10.41
          6 |        333        3.33       13.74
          7 |        483        4.83       18.57
          8 |        521        5.21       23.78
          9 |        636        6.36       30.14
         10 |        629        6.29       36.43
         11 |      1,231       12.31       48.74
         12 |        719        7.19       55.93
         13 |      1,720       17.20       73.13
         14 |        695        6.95       80.08
         15 |        796        7.96       88.04
         16 |        527        5.27       93.31
         17 |        226        2.26       95.57
         18 |         89        0.89       96.46
         19 |         79        0.79       97.25
         20 |         40        0.40       97.65
         21 |         81        0.81       98.46
         22 |         22        0.22       98.68
         23 |         11        0.11       98.79
         24 |          7        0.07       98.86
         25 |          4        0.04       98.90
         26 |         14        0.14       99.04
         27 |          9        0.09       99.13
         28 |         87        0.87      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016